NAME

KEYWORDS

SYNOPSIS

Flags:

--overwrite

Allow output files to overwrite existing files

--verbose

Verbose module output

--quiet

Quiet module output

Parameters:

input=name

Name of input vector map

type=string[,string,...]

Feature type

Options: point,centroid,line,boundary,face,kernel

Default: point,centroid,line,boundary,face,kernel

rast=name

Elevation raster map for height extraction

output=name

Name for output vector map

method=string

Sampling method

Options: nearest,bilinear,cubic

Default: nearest

nearest: nearest neighbor

bilinear: bilinear interpolation

cubic: cubic convolution interpolation

scale=float

Scale sampled raster values

Default: 1.0

where=sql_query

WHERE conditions of SQL statement without 'where' keyword

Example: income < 1000 and inhab >= 10000

layer=integer

Layer number

Layer is only used for WHERE SQL statement

Default: 1

null_value=float

Vector Z value for unknown height

Will set Z to this value, if value from raster map can not be read

DESCRIPTION

v.drape converts 2D/3D vector data into 3D vector format via sampling of an elevation surface. Three sampling algorithms adapted from v.sample were incorporated into this module: nearest neighbor, bilinear, and cubic convultion.

v.drape will skip vector features outside of current computational region or where raster map has NULL value. It's possible to include all vector features by specifying height value that will be assigned to verticles whose values can not be determined from raster map.

NOTES

Additional vertices can be added to the input 2D vector map with v.split.

The module can be used in conjunction with v.out.pov and r.out.pov to export a complete set of vector and raster data for display in POVRAY.

EXAMPLES

Spearfish example:

v.drape in=roads rast=elevation.10m method=bilinear out=roads3d
v.info roads3d

Create 3D vector roads map containing only "unimproved" roads. Set road height to 1000 m for all parts without height information.

v.drape input=roads type=line rast=elevation.dem output=roads_3d \
method=nearest scale=1.0 where='cat=5' layer=1 null_value=1000

POVRAY EXAMPLE

#export the vector data
v.drape in=roads out=roads3d rast=elevation.10m
v.out.pov roads3d out=roads3d.pov
#export the raster data
r.out.pov elevation.10m tga=elevation.tga
r.out.png landcover.30m out=landcover30m.png

# now write a complete povray-script and launch povray

SEE ALSO

AUTHOR

Last changed: $Date: 2008-11-03 02:04:48 -0800 (Mon, 03 Nov 2008) $

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